Why doesn't Iref_sd = 0 when 0 is input to Tref and ωm in the ACIM control reference?

Hi Team,

I am studying vector control, so this may be a strange question.

I am looking to build an ACIM control reference in the architecture in the link below to implement vector control (FOC) of an AC induction motor.

URL: https://jp.mathworks.com/help/mcb/gs/implement-motor-speed-control-by-using-field-oriented-control-foc.html?s_tid=srchtitle_ site_search_1_%25E3%2583%2599%25E3%2582%25AF%25E3%2583%2588%25E3%2583%25AB%25E5%2588%25B6%25E5%25BE%25A1

Assuming that the feedback speed and reference speed (torque) are 0, the following simulation was performed to generate the reference current Iref.

　Simulation Configuration

　　・ACIM control reference block (default value)

　　・Constant block (0)

　　・Scope

Iref = 0 in the forecast, but in the simulation it was about 0.24.

So my question is.

Why doesn't Iref_sd = 0 when I enter 0 for Tref and ωm in the ACIM control reference block with the parameters set to their default values?

Best regards

Answer 1

[Sam Chak]

Hi @中嶋

Your and according to mathematical model of the AC Induction Motor (ACIM) Control Reference block, if the condition is true, then the minimum function will be triggered. The block output is .

https://www.mathworks.com/help/mcb/ref/acimcontrolreference.html#mw_591bf425-f633-480f-a6e1-20aa24bb5f66

Answer 2

[中嶋]

Thank you for your response.

When the feedback value and the reference value match,

I have found that Isd_ref=Isd_0

and

Isd_0 is calculated by magnetizing inductance (Lm) and d-axis flux linkage of the rotor (λrd).

It seems that vector control requires a good understanding of Lm and λrd.

I will study them again.

Thank you again.